DE-A-2,235,119 describes an embodiment in which a hook moves between front and rear limiting positions along a trajectory which is approximately circular about a given longitudinal axis of a bore. The bore itself has a shape which is cylindrical about its axis. The bore permanently houses the hook which never penetrates a slit in the plate cylinder.
The fastening of the posterior end fold of the plate onto the hook must therefore take place relatively far from the external surface of the plate cylinder, through the slit connecting the bore to the plate cylinder surface. This makes for a long and difficult fastening operation, unless a relatively wide slit is provided, which disadvantageously provides a correspondingly larger printing gap. Furthermore, between the mouth of the slit in the external plate cylinder surface and the posterior end fold the plate has, in engagement with the hook, an end region which cannot be used for printing. The size of this region is relatively large, which makes it necessary to overdimension the plate for a given printing format.